Package: src:linux
Version: 4.6.4-1
Severity: wishlist
Tags: patch
In March I had developed a kernel patch that allows to set the TMDS
frequency for radeon cards by a new kernel parameter called
radeon.hdmimhz if the automatically set frequency stays either behind of
what has been advertised for the card or by what is achievable through
overclocking. A similar parameter for nvidia/nouveau cards is already
available somewhat longer. However up to now the patch has not been
accepted into the mainline kernel simply because radeon developers are
not encouraged to enable this feature for elder cards by the policy of
their sponsors. Here are some of my considerations which you may take
into account when deciding about the acceptance of the patch for Debian
Stretch:
* the patch is very simple, just a few lines of code
* behaviour of the kernel is not influenced by the patch except when
the user gives a non-zero value for radeon.hdmimhz
* the patch has already wheathered time; the surrounding code has
more or less remained unchanged since March
* long time usage experience is already available at least with the
radeon R5 230 card as well as different monitors; my personal experience
with the patch is very good
* the patch provides a huge advantage at least for all people who
still use Core 2 based systems:
- elder radeon cards can be made UHD ready
- the R5 230 card supported by the patch may be the only one of its
type that has a single slot height - and it has been sold to me as
DVI-UltraHD ready; however this feature can not be exploited without the
kernel patch
- newer radeon cards are often incompatible with elder Core 2 systems
* at least nouveau developers say that by overclocking your TMDS it
would rarely be possible to damage a card; a way of proceeding
considered safe can be read in the linked article
(https://www.elstel.org/software/hunt-for-4K-UHD-2160p.html.en ; the
article is no more completely new and it will be updated soon.).
P.S.: The attached patches are for application at the 4.8.0-rcX
kernels; however the same patch has also proven to work well for
4.6.x/Debian. If you do not want to update 4.6.0-1 then I`d apply for
inclusion of this patch with the adoption of 4.8.0.
-- System Information:
Debian Release: stretch/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.8.0-rc6+ (SMP w/4 CPU cores)
Locale: LANG=de_AT.utf8, LC_CTYPE=de_AT.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages linux-image-4.6.0-1-amd64 depends on:
ii initramfs-tools [linux-initramfs-tool] 0.125
ii kmod 22-1.1
ii linux-base 4.4
Versions of packages linux-image-4.6.0-1-amd64 recommends:
ii firmware-linux-free 3.4
pn irqbalance <none>
Versions of packages linux-image-4.6.0-1-amd64 suggests:
pn debian-kernel-handbook <none>
ii grub-pc 2.02~beta2-36
pn linux-doc-4.6 <none>
Versions of packages linux-image-4.6.0-1-amd64 is related to:
ii firmware-amd-graphics 20160110-1
ii firmware-atheros 20160110-1
ii firmware-bnx2 20160110-1
ii firmware-bnx2x 20160110-1
ii firmware-brcm80211 20160110-1
ii firmware-cavium 20160110-1
ii firmware-intel-sound 20160110-1
ii firmware-intelwimax 20160110-1
ii firmware-ipw2x00 20160110-1
ii firmware-ivtv 20160110-1
ii firmware-iwlwifi 20160110-1
ii firmware-libertas 20160110-1
pn firmware-linux-nonfree <none>
ii firmware-misc-nonfree 20160110-1
ii firmware-myricom 20160110-1
ii firmware-netxen 20160110-1
ii firmware-qlogic 20160110-1
ii firmware-realtek 20160110-1
ii firmware-samsung 20160110-1
ii firmware-siano 20160110-1
ii firmware-ti-connectivity 20160110-1
pn xen-hypervisor <none>
